1. Field of the Invention
The present invention relates to improved deicing compositions comprising magnesium chloride and potassium sulfate.
2. Description of Related Art
Freezing-point lowering compositions (or deicing compositions) are commonly used to reduce or prevent the build-up of ice and snow on various surfaces, such as roadways, sidewalks, and driveways. They work by lowering the freezing point of the ice itself, so that the ice and snow melt. Traditional solid deicing compositions include rock salt (NaCl), calcium chloride, and urea, with rock salt being the most commonly used. Liquid deicing compositions can also be used and include ethylene and propylene glycol and various alcohols.
Traditional deicing compositions have a number of drawbacks, including their corrosive effect on the surrounding environment, as well as their negative impact on soil, water, and animals. For example, sodium chloride accumulation via water runoff from traditional deicing salt tends to diminish permeability of the soil and increase its alkalinity. High levels of sodium also cause the loss of vital plant nutrients such as potassium, calcium, and magnesium from surrounding vegetation. Chloride salts can also inhibit water uptake by roots of plants and trees. As a result, many traditional deicing salts damage vegetation, such as trees and grass, along roadways where salt is applied. Traditional chloride salts, such as sodium chloride and calcium chloride, can also be harmful to the skin of animals, such as pet paws, and have a corrosive effect on motor vehicles and cause surface damage or scaling on concrete. Likewise, glycols can be detrimental to aquatic life and to sewage treatment processes, while alcohols have toxic effects and high volatility, particularly at low molecular weights. Thus, attempts have been made to create new deicing compositions that minimize impact on the environment including the people and pets who come into contact with such compositions. However, existing “pet friendly” deicing compositions have poor ice melting capabilities. Urea, an ingredient commonly used in pet friendly deicers is also prone to being blown away even before melting begins, and is very susceptible to refreezing. Accordingly, there remains a need in the art for pet friendly deicing compositions that also have a less corrosive effect on the environment without sacrificing melting performance.